We will investigate the role of vitamin E in preventing or modifying the course of oxygen-induced pulmonary injury in premature infants requiring oxygen and assisted ventilation during treatment for respiratory distress syndrome and in newborn rabbits. In the human studies, the effect of vitamin E on the development of bronchopulmonary dysplasia will be assessed using clinical and radiographic criteria. We will also determine the effect of vitamine E on the development of bronchopulmonary dysplasia will be assessed using clinical and radiographic criteria. We will also determine the effect of vitamin E on the incidence of retrolental fibroplasia. The investigations in newborn rabbits will utilize normal and vitamin E-deprived animals who are exposed to room air or hyperoxia (100% oxygen). Studies to be carried out include measurement of lipid peroxide formation in lung and red cells in controls and different vitamin E groups, determination of phospholipid synthesis using lung slice and lavage techniques, determination of influences on oxidative metabolism and on glutathione reductase and peroxidase activities. Pathological correlations will be carried out at the light and electron microscopic levels. These studies will hopefully permit us to confirm preliminary human evidence suggesting a protective effect of vitamin E in preventing severe bronchopulmonary dysplasia and should also provide new information concerning oxygen toxicity and effects of vitamin E on lung function and metabolism in the newborn.